Imperius Curse ('Imperio') The first of the three Unforgivable Curses, Imperius gives the spell-caster total control over their subject. As fake-Moody explains as he demonstrates on a spider: 'I could make it jump out of the window, drown itself, throw itself down one of your throats…'
The darkest of the Dark Arts, Harry Potter unforgivable curses are the Cruciatus Curse, the Imperius Curse, and the Killing Curse. Although the curses are highly illegal, Harry using Unforgivable Curses happened, but he uses them once he was thrust into the Second Wizarding War.
The Imperius Curse (Imperio) was a tool of the Dark Arts, and was one of the three Unforgivable Curses. When cast successfully, the curse placed the victim completely under the caster's control, making the victim unquestionably obedient to the caster. A person under the curse was said to be Imperiused.
They were first classified as "Unforgivable" in 1717. They are the Killing Curse, Avada Kedavra, the Cruciatus Curse, Crucio, and the Imperius Curse, Imperio.
I personally find Crucio actually the most effective of the 3 unforgiveable curses with Imperio being the 2nd most useful. Avada Kedavra I find actually the most difficult due to the insanely long cooldown on it basically necessitating Crucio mastery and the mastery for it.
Hermione Granger was always referred to as being the brains out of the trio and while that is true, her endurance of the Cruciatus Curse at the hands of Bellatrix show that she was as physically and emotionally tough as she was smart.
Cruciatus Curse ('Crucio')
'Better dead than what happened to them,' was what Moody said of the Longbottoms' fate, and there's a sad ring of truth to that statement. Harry tried to use this spell himself. The first time was against Bellatrix after she had killed Sirius.
Harry Used The Imperius Curse Multiple Times During The Gringotts Heist. Harry does use Unforgivable Curses in the last movie, despite Harry Potter using Unforgivable Curses seeming unlikely because of his hero status. Death Eaters had a history of using Imperio to make innocent victims do their bidding.
By contrast, he's never used Avada Kedavra, far less in a combat situation. His other uses of Unforgivable Curses have had mixed results: although he used the Imperius curse successfully while breaking into Gringotts, his initial attempts to use the Cruciatus curse on Bellatrix and Snape were unsuccessful.
In the Harry Potter series, Bellatrix Lestrange used the spell "Avada Kedavra" to kill Sirius Black.
Description and effects: The Killing Curse is a lethal curse that causes instantaneous death upon impact. Compatibility with Bellatrix's death: Bellatrix's sudden death aligns with the effects of the Avada Kedavra curse.
Avada Kedavra, also known as the Killing Curse, kills a person instantaneously and without injury. There is few counter for it, and only one person, Harry Potter, has ever survived it with Sacrificial Protection that has been endowed upon Harry Potter by His Mother Love for Him.
The Avada Kedavra – the killing curse from the Harry Potter Wizarding World is unforgivable, cannot be blocked, and is colored green. Every time books or movies make mention of the spell, they insist on those things.
In Harry's case, he is consumed with a righteous anger rather than a malicious intent. Draco Malfoy attempts to use this curse on Harry at one point, but is forestalled by Harry's use of Sectumsempra.
Ron never cast any kind of curse on Nagini, not in the book anyways. And there's no confirmation that the spell he used on her in the movies was the Killing Curse. Avada Kedavra isn't the only spell that creates green light, after all.
Draco Malfoy (Cruciatus and Imperius Curses)
Although the use of these curses is rightly unforgivable, it's important to note that Draco never used them for his own benefit. It was always the pressure from Lord Voldemort that forced Draco into his crimes.
Why doesn t Harry use Avada Kedavra on Bellatrix? Harry didn't use that spell because he cannot bring himself to kill anyone. He is not a killer.
Voldemort killed Snape in Harry Potter And The Deathly Hallows Part 2 using his Horcrux snake Nagini instead of his favorite Unforgivable Curse, Avada Kedavra.
The author explicitly states that both women were fighting to kill, despite Molly refraining from casting the Unforgivable curse Avada Kedavra. The result of the duel actually comes about as a result of nothing more than spectacular accuracy on Weasley's part.
During the task, Barty Crouch Jr, posing as Alastor Moody by way of the Polyjuice Potion, managed to place the Imperius Curse on Viktor as part of his plot to steer Harry Potter to victory in the Tournament. Under Moody's control, he caught up with Cedric and performed the Cruciatus Curse on him.
Oh that's easy, because there wasn't any witnesses from the ministry that he performed the curse, Dumbledore will not hand him to the authorities because he would be in more danger and Bella, being a convicted death eater scapee won't denounce him either.
5 Bellatrix Lestrange: The Cruciatus Curse.
Sirius scolds Harry, "what do you think you were playing at, walking off into the forest with Viktor Krum?" (29.92). And during the third task, Viktor casts the Cruciatus Curse on Cedric Diggory until Harry comes along and Stuns him. (It turns out later that Moody used the Imperius Curse on Viktor to make him do this.
Eventually, you'll come to a door that requires someone to perform Crucio on the other. You can either perform the curse yourself or have Sebastian perform it on you. Either way, you'll then be able to use the spell, which does damage over time to any enemy that you use it on.